(SQL Server) SHA256 Hash the Bytes Represented in a Hex String

Demonstrates how to compute the SHA256 hash of the bytes represented by a hexidecimal encoded string, and return the hash bytes as an hex encoded string.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @success int

    -- We wish to compute the SHA256 hash of the bytes 0x6C 0xF8 0xEA 0x51 0xE4 0xE0 0xF5 0x99 0xCF ...
    DECLARE @src nvarchar(4000)
    SELECT @src = '6CF8EA51E4E0F599CF03EC8D58C3DCBC9C889A77FB2816B40DE25C2EC54E98A67EA517B'

    DECLARE @bd int
    -- Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @bd OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @bd, 'AppendEncoded', @success OUT, @src, 'hex'

    -- The bd now contains the bytes 0x6C 0xF8 0xEA 0x51 0xE4 0xE0 0xF5 0x99 0xCF ...

    DECLARE @crypt int
    -- Use "Chilkat_9_5_0.Crypt2" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT

    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'sha256'
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex'

    -- Hash the bytes contained in bd, and return the 32-byte SHA256 hash as a hexidecimal encoded string.
    DECLARE @result nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'HashBdENC', @result OUT, @bd

    PRINT @result

    EXEC @hr = sp_OADestroy @bd
    EXEC @hr = sp_OADestroy @crypt


END
GO